Re: [PATCH 0/6] lib/lzo: performance improvements

[Sergey Senozhatsky]

On (11/21/18 12:06), Dave Rodgman wrote:
> 
> Overall, performance is improved by around 1.1 - 4.8x (data-dependent: data
> with many zero runs shows higher improvement). Under real-world testing with
> zram, time spent in (de)compression during swapping is reduced by around 27%.

Impressive.

I think we usually Cc Greg Kroah-Hartman and Andrew Morton on
lzo/lz4 patches.

> The graph below shows the weighted round-trip throughput of lzo, lz4 and
> lzo-rle, for randomly generated 4k chunks of data with varying levels of
> entropy. (To calculate weighted round-trip throughput, compression performance
> is emphasised to reflect the fact that zram does around 2.25x more compression
> than decompression.

Right. The number is data dependent. Not all swapped out pages can be
compressed; compressed pages that end up being >= zs_huge_class_size() are
considered incompressible and stored as it.

I'd say that on my setups around 50-60% of pages are incompressible.

	-ss